The Facciatone terrace at sunset

In 1339 Siena began a cathedral so vast that the existing Duomo would have been only its transept. The plague stopped the work, and the huge unfinished wall still stands — the Facciatone. A spiral staircase inside the Museo dell'Opera leads out onto the top of it: a walkway a few metres wide, open to the sky.

It is the best viewpoint in the city and, unusually, it is high without being distant. The Duomo's striped campanile is close enough to fill the background of a portrait, while on the other side the terracotta roofs run down to the Torre del Mangia. Late light comes from behind the cathedral, so turn towards the Mangia for lit faces and keep the Duomo for silhouettes.

Access is by museum ticket and the stair is narrow, steep and single-file in places — check the opening hours, which change with the season and end well before dark in winter. The terrace is small: with more than a handful of visitors it becomes a queue rather than a shoot, so aim for opening time or the last admission slot.